Type 2
Crigler-Najjar syndrome
Crigler-Najjar syndrome (CNS) is a very rare genetic condition that affects the way the body processes bilirubin. Type 2 is a less severe form of the condition. Most children with type 2 respond well to medication and can lead relatively normal lives.
The information on this page is for:
- Parents of children with Crigler-Najjar type 2.
- Family, friends, carers, and healthcare professionals.
On this page:
What is type 2 Crigler-Najjar syndrome?
Type 2 is a less severe form of Crigler-Najjar syndrome. In type 2, the body produces a small amount of the UDPCT protein. Symptoms are generally milder and children are less likely to develop brain damage (kernicterus). They also respond to some medications, provided they are started early.
There is no cure for CNS type 2, but most children are well controlled on medication. Even with some jaundice, they are likely to survive into adulthood. Many will live a relatively normal life.
What are the signs and symptoms?
Symptoms in type 2 Crigler-Najjar syndrome are milder than in type 1. Children may develop yellowing of the whites of the eyes and skin (jaundice). In some children, this may only be triggered at certain times, such as:
- when they are sick
- when they have not eaten for a long period of time
- when they have a general anaesthesia
How is it treated?
The main treatment for Crigler-Najjar syndrome type 2 is phenobarbital. This drug helps reduce bilirubin levels in the blood. But if bilirubin levels continue to rise, phototherapy and other treatments may be needed.
Phenobarbitol
Phenobarbitol is the main treatment for Crigler-Najjar syndrome type 2. This drug helps reduce bilirubin levels in the blood. Bilirubin levels can still rise if a child has another illness, hasn’t eaten for some time, or if they experience emotional stress. In such cases, phototherapy and other treatments may be needed.
Phototherapy
During this treatment, a child’s bare skin is exposed to intense light. It is similar to a tanning bed. Special eyewear is used to protect the eyes.
This treatment helps the body break down and remove bilirubin. But phototherapy is a long process and takes around 12 hours per day. This can significantly impact a child’s quality of life. Over time, a child’s skin will also thicken as a result of this treatment, so it becomes less effective.
Intravenous (IV) fluid therapy
This is a way of getting more fluids into the body. A narrow, bendy tube (cannula) is put into a vein using a needle. Fluids and medicines are put into the cannula and go straight into the bloodstream.
Albumin administration
Albumin is a type of protein found in blood plasma (the clear liquid part of the blood). Albumin can be used as a treatment by injecting it into a vein.
Plasmapheresis
This treatment involves separating the liquid part of the blood (plasma) from the blood cells. The plasma is replaced with another liquid (saline or albumin). Or it is treated and returned to the body.
Drug treatments and new therapies
Drug treatments may be used to manage symptoms and complications. Other treatments are also being tested by researchers. This includes hepatocyte transplantation and gene therapies.
Liver transplant
The only definitive treatment for uncontrollable CNS type 2 is a liver transplant. It will only be considered if other treatments no longer control the condition.
A transplant is an operation to remove a liver that does not work. It is replaced with a whole or part liver from another person (donor). This could be a deceased or live donor. The new liver provides cells and proteins that can break down bilirubin.
If the operation is successful, it can significantly improve a child’s quality of life. But it is important to remember that a liver transplant is a major operation. It will only be done after the benefits and risks have been carefully weighed up.
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This content was last reviewed: December 2024
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We would like to thank everyone who helped with creating and reviewing this page. Information within this leaflet has been produced with input from the three specialist paediatric liver centres in the UK. And with parents and families.
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Everyone’s experience of liver disease will be different. Always talk to your specialist medical team for personal advice.
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